Terbium-158 (Tb-158)

Identity

Protons

65

Neutrons

93

Mass number

158

Mass

157.9 ± 1.4 u

Mass excess

-69.471 MeV

Spin

3-*

Stability

Half-life: 180 years

Natural occurrence

Not found in nature

Decays to

• positron emission 83.4 % → Gd-158
• beta minus 16.6 % → Dy-158